does anyone else have this?
I only noticed it last year when I had a new fridge installed. Ever since then, come 6.00 pm, I notice that the lamps occasionally dim and the microwave/kettle/hob go slow (takes feckin' ages to boil the kettle).
The builder who installed the fridge freezer got his electrician mate to come and check the wiring (socket) as it was cracked and he said that the house had really old wiring. I showed him my survey from the previous year's move which said that the house had been re-wired six years previously. He just said "They're lying - it's old." 
Shall I call NPower / another electrician / the original builder / the previous owner?